1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * Definitions for the IP module. 7 * 8 * Version: @(#)ip.h 1.0.2 05/07/93 9 * 10 * Authors: Ross Biro 11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 12 * Alan Cox, <gw4pts@gw4pts.ampr.org> 13 * 14 * Changes: 15 * Mike McLagan : Routing by source 16 * 17 * This program is free software; you can redistribute it and/or 18 * modify it under the terms of the GNU General Public License 19 * as published by the Free Software Foundation; either version 20 * 2 of the License, or (at your option) any later version. 21 */ 22 #ifndef _IP_H 23 #define _IP_H 24 25 #include <linux/config.h> 26 #include <linux/types.h> 27 #include <linux/ip.h> 28 #include <linux/in.h> 29 30 #include <net/inet_sock.h> 31 #include <net/snmp.h> 32 33 struct sock; 34 35 struct inet_skb_parm 36 { 37 struct ip_options opt; /* Compiled IP options */ 38 unsigned char flags; 39 40 #define IPSKB_FORWARDED 1 41 #define IPSKB_XFRM_TUNNEL_SIZE 2 42 #define IPSKB_XFRM_TRANSFORMED 4 43 #define IPSKB_FRAG_COMPLETE 8 44 #define IPSKB_REROUTED 16 45 }; 46 47 struct ipcm_cookie 48 { 49 u32 addr; 50 int oif; 51 struct ip_options *opt; 52 }; 53 54 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) 55 56 struct ip_ra_chain 57 { 58 struct ip_ra_chain *next; 59 struct sock *sk; 60 void (*destructor)(struct sock *); 61 }; 62 63 extern struct ip_ra_chain *ip_ra_chain; 64 extern rwlock_t ip_ra_lock; 65 66 /* IP flags. */ 67 #define IP_CE 0x8000 /* Flag: "Congestion" */ 68 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 69 #define IP_MF 0x2000 /* Flag: "More Fragments" */ 70 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ 71 72 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ 73 74 struct msghdr; 75 struct net_device; 76 struct packet_type; 77 struct rtable; 78 struct sk_buff; 79 struct sockaddr; 80 81 extern void ip_mc_dropsocket(struct sock *); 82 extern void ip_mc_dropdevice(struct net_device *dev); 83 extern int igmp_mc_proc_init(void); 84 85 /* 86 * Functions provided by ip.c 87 */ 88 89 extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, 90 u32 saddr, u32 daddr, 91 struct ip_options *opt); 92 extern int ip_rcv(struct sk_buff *skb, struct net_device *dev, 93 struct packet_type *pt, struct net_device *orig_dev); 94 extern int ip_local_deliver(struct sk_buff *skb); 95 extern int ip_mr_input(struct sk_buff *skb); 96 extern int ip_output(struct sk_buff *skb); 97 extern int ip_mc_output(struct sk_buff *skb); 98 extern int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)); 99 extern int ip_do_nat(struct sk_buff *skb); 100 extern void ip_send_check(struct iphdr *ip); 101 extern int ip_queue_xmit(struct sk_buff *skb, int ipfragok); 102 extern void ip_init(void); 103 extern int ip_append_data(struct sock *sk, 104 int getfrag(void *from, char *to, int offset, int len, 105 int odd, struct sk_buff *skb), 106 void *from, int len, int protolen, 107 struct ipcm_cookie *ipc, 108 struct rtable *rt, 109 unsigned int flags); 110 extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb); 111 extern ssize_t ip_append_page(struct sock *sk, struct page *page, 112 int offset, size_t size, int flags); 113 extern int ip_push_pending_frames(struct sock *sk); 114 extern void ip_flush_pending_frames(struct sock *sk); 115 116 /* datagram.c */ 117 extern int ip4_datagram_connect(struct sock *sk, 118 struct sockaddr *uaddr, int addr_len); 119 120 /* 121 * Map a multicast IP onto multicast MAC for type Token Ring. 122 * This conforms to RFC1469 Option 2 Multicasting i.e. 123 * using a functional address to transmit / receive 124 * multicast packets. 125 */ 126 127 static inline void ip_tr_mc_map(u32 addr, char *buf) 128 { 129 buf[0]=0xC0; 130 buf[1]=0x00; 131 buf[2]=0x00; 132 buf[3]=0x04; 133 buf[4]=0x00; 134 buf[5]=0x00; 135 } 136 137 struct ip_reply_arg { 138 struct kvec iov[1]; 139 u32 csum; 140 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 141 /* -1 if not needed */ 142 }; 143 144 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, 145 unsigned int len); 146 147 struct ipv4_config 148 { 149 int log_martians; 150 int autoconfig; 151 int no_pmtu_disc; 152 }; 153 154 extern struct ipv4_config ipv4_config; 155 DECLARE_SNMP_STAT(struct ipstats_mib, ip_statistics); 156 #define IP_INC_STATS(field) SNMP_INC_STATS(ip_statistics, field) 157 #define IP_INC_STATS_BH(field) SNMP_INC_STATS_BH(ip_statistics, field) 158 #define IP_INC_STATS_USER(field) SNMP_INC_STATS_USER(ip_statistics, field) 159 DECLARE_SNMP_STAT(struct linux_mib, net_statistics); 160 #define NET_INC_STATS(field) SNMP_INC_STATS(net_statistics, field) 161 #define NET_INC_STATS_BH(field) SNMP_INC_STATS_BH(net_statistics, field) 162 #define NET_INC_STATS_USER(field) SNMP_INC_STATS_USER(net_statistics, field) 163 #define NET_ADD_STATS_BH(field, adnd) SNMP_ADD_STATS_BH(net_statistics, field, adnd) 164 #define NET_ADD_STATS_USER(field, adnd) SNMP_ADD_STATS_USER(net_statistics, field, adnd) 165 166 extern int sysctl_local_port_range[2]; 167 extern int sysctl_ip_default_ttl; 168 extern int sysctl_ip_nonlocal_bind; 169 170 /* From ip_fragment.c */ 171 extern int sysctl_ipfrag_high_thresh; 172 extern int sysctl_ipfrag_low_thresh; 173 extern int sysctl_ipfrag_time; 174 extern int sysctl_ipfrag_secret_interval; 175 extern int sysctl_ipfrag_max_dist; 176 177 /* From inetpeer.c */ 178 extern int inet_peer_threshold; 179 extern int inet_peer_minttl; 180 extern int inet_peer_maxttl; 181 extern int inet_peer_gc_mintime; 182 extern int inet_peer_gc_maxtime; 183 184 /* From ip_output.c */ 185 extern int sysctl_ip_dynaddr; 186 187 extern void ipfrag_init(void); 188 189 #ifdef CONFIG_INET 190 #include <net/dst.h> 191 192 /* The function in 2.2 was invalid, producing wrong result for 193 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 194 static inline 195 int ip_decrease_ttl(struct iphdr *iph) 196 { 197 u32 check = iph->check; 198 check += htons(0x0100); 199 iph->check = check + (check>=0xFFFF); 200 return --iph->ttl; 201 } 202 203 static inline 204 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 205 { 206 return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 207 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 208 !(dst_metric(dst, RTAX_LOCK)&(1<<RTAX_MTU)))); 209 } 210 211 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 212 213 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk) 214 { 215 if (iph->frag_off & htons(IP_DF)) { 216 /* This is only to work around buggy Windows95/2000 217 * VJ compression implementations. If the ID field 218 * does not change, they drop every other packet in 219 * a TCP stream using header compression. 220 */ 221 iph->id = (sk && inet_sk(sk)->daddr) ? 222 htons(inet_sk(sk)->id++) : 0; 223 } else 224 __ip_select_ident(iph, dst, 0); 225 } 226 227 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more) 228 { 229 if (iph->frag_off & htons(IP_DF)) { 230 if (sk && inet_sk(sk)->daddr) { 231 iph->id = htons(inet_sk(sk)->id); 232 inet_sk(sk)->id += 1 + more; 233 } else 234 iph->id = 0; 235 } else 236 __ip_select_ident(iph, dst, more); 237 } 238 239 /* 240 * Map a multicast IP onto multicast MAC for type ethernet. 241 */ 242 243 static inline void ip_eth_mc_map(u32 addr, char *buf) 244 { 245 addr=ntohl(addr); 246 buf[0]=0x01; 247 buf[1]=0x00; 248 buf[2]=0x5e; 249 buf[5]=addr&0xFF; 250 addr>>=8; 251 buf[4]=addr&0xFF; 252 addr>>=8; 253 buf[3]=addr&0x7F; 254 } 255 256 /* 257 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 258 * Leave P_Key as 0 to be filled in by driver. 259 */ 260 261 static inline void ip_ib_mc_map(u32 addr, char *buf) 262 { 263 buf[0] = 0; /* Reserved */ 264 buf[1] = 0xff; /* Multicast QPN */ 265 buf[2] = 0xff; 266 buf[3] = 0xff; 267 addr = ntohl(addr); 268 buf[4] = 0xff; 269 buf[5] = 0x12; /* link local scope */ 270 buf[6] = 0x40; /* IPv4 signature */ 271 buf[7] = 0x1b; 272 buf[8] = 0; /* P_Key */ 273 buf[9] = 0; 274 buf[10] = 0; 275 buf[11] = 0; 276 buf[12] = 0; 277 buf[13] = 0; 278 buf[14] = 0; 279 buf[15] = 0; 280 buf[19] = addr & 0xff; 281 addr >>= 8; 282 buf[18] = addr & 0xff; 283 addr >>= 8; 284 buf[17] = addr & 0xff; 285 addr >>= 8; 286 buf[16] = addr & 0x0f; 287 } 288 289 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 290 #include <linux/ipv6.h> 291 #endif 292 293 static __inline__ void inet_reset_saddr(struct sock *sk) 294 { 295 inet_sk(sk)->rcv_saddr = inet_sk(sk)->saddr = 0; 296 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 297 if (sk->sk_family == PF_INET6) { 298 struct ipv6_pinfo *np = inet6_sk(sk); 299 300 memset(&np->saddr, 0, sizeof(np->saddr)); 301 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 302 } 303 #endif 304 } 305 306 #endif 307 308 extern int ip_call_ra_chain(struct sk_buff *skb); 309 310 /* 311 * Functions provided by ip_fragment.o 312 */ 313 314 enum ip_defrag_users 315 { 316 IP_DEFRAG_LOCAL_DELIVER, 317 IP_DEFRAG_CALL_RA_CHAIN, 318 IP_DEFRAG_CONNTRACK_IN, 319 IP_DEFRAG_CONNTRACK_OUT, 320 IP_DEFRAG_VS_IN, 321 IP_DEFRAG_VS_OUT, 322 IP_DEFRAG_VS_FWD 323 }; 324 325 struct sk_buff *ip_defrag(struct sk_buff *skb, u32 user); 326 extern int ip_frag_nqueues; 327 extern atomic_t ip_frag_mem; 328 329 /* 330 * Functions provided by ip_forward.c 331 */ 332 333 extern int ip_forward(struct sk_buff *skb); 334 extern int ip_net_unreachable(struct sk_buff *skb); 335 336 /* 337 * Functions provided by ip_options.c 338 */ 339 340 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, u32 daddr, struct rtable *rt, int is_frag); 341 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 342 extern void ip_options_fragment(struct sk_buff *skb); 343 extern int ip_options_compile(struct ip_options *opt, struct sk_buff *skb); 344 extern int ip_options_get(struct ip_options **optp, 345 unsigned char *data, int optlen); 346 extern int ip_options_get_from_user(struct ip_options **optp, 347 unsigned char __user *data, int optlen); 348 extern void ip_options_undo(struct ip_options * opt); 349 extern void ip_forward_options(struct sk_buff *skb); 350 extern int ip_options_rcv_srr(struct sk_buff *skb); 351 352 /* 353 * Functions provided by ip_sockglue.c 354 */ 355 356 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 357 extern int ip_cmsg_send(struct msghdr *msg, struct ipcm_cookie *ipc); 358 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen); 359 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); 360 extern int compat_ip_setsockopt(struct sock *sk, int level, 361 int optname, char __user *optval, int optlen); 362 extern int compat_ip_getsockopt(struct sock *sk, int level, 363 int optname, char __user *optval, int __user *optlen); 364 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 365 366 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 367 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 368 u16 port, u32 info, u8 *payload); 369 extern void ip_local_error(struct sock *sk, int err, u32 daddr, u16 dport, 370 u32 info); 371 372 /* sysctl helpers - any sysctl which holds a value that ends up being 373 * fed into the routing cache should use these handlers. 374 */ 375 int ipv4_doint_and_flush(ctl_table *ctl, int write, 376 struct file* filp, void __user *buffer, 377 size_t *lenp, loff_t *ppos); 378 int ipv4_doint_and_flush_strategy(ctl_table *table, int __user *name, int nlen, 379 void __user *oldval, size_t __user *oldlenp, 380 void __user *newval, size_t newlen, 381 void **context); 382 #ifdef CONFIG_PROC_FS 383 extern int ip_misc_proc_init(void); 384 #endif 385 386 extern struct ctl_table ipv4_table[]; 387 388 #endif /* _IP_H */ 389